Fig. 2: The HIV epidemic among men who have sex with men (MSM) in Taiwan, 1990–2019.
From: A modeling study of pre-exposure prophylaxis to eliminate HIV in Taiwan by 2030
The numbers of notified MSM HIV diagnoses (presented as bars) are based on data from the Taiwan national HIV registry (see Statistics and Reproducibility section). We fitted the deterministic model to the actual Taiwan HIV epidemic curve from 1990 to 2019 by age strata, using the least square method (presented as lines). To account for the trend of changing sexual behaviors over time, the model fitting was separately conducted for each era during which parameters may have increased or decreased linearly: 1990–1997 (before ART), 1997–2001 (introduction of ART), 2001–2005 (impact of the 2003 SARS outbreak in Taiwan), 2005–2009 (rise of internet chat room for sexual partner-seeking), 2009–2013 (rise of mobile phone apps for sexual partner-seeking), 2013–2017 (chemsex-associated increase in HIV transmission), and 2017–2019 (status quo), respectively. Refer to “Methods”, Supplementary Data 1, Supplementary Tables 1–8, and Supplementary Figs. 4 and 5 for details on model fitting and parameterization.
